The drive to net zero carbon emissions
Following an appearance on the British Property Federation’s panel discussion on future proofing buildings of the past, Laura Jockers, Head of Sustainability, outlines in EG this week how retrofitting period buildings can help in the process in reaching net zero targets.
In the drive to achieve net zero carbon emissions in the built environment, the spotlight often falls on new buildings and their sustainability credentials. However, the UK has a huge number of period buildings which also need to be addressed.
On the upside, these buildings have been around for a long time and are often recycled for a number of uses. The switch from residential to commercial and back again is not uncommon – particularly in London. Given that one of the most ruinous processes in achieving carbon neutrality is demolishing young buildings (circa 20-30 years) and building new replacements, the retention of old buildings is clearly a plus.
The downside is that their fabric, configuration and operation is invariably not conducive to scoring well on key sustainability metrics. Although historic building fabric will often perform better than assumed, large amounts of heat can be lost through the building envelope.
Rectifying these issues without disturbing the historic features or creating unintended consequences such as condensation makes retrofit especially difficult. And as the nature of historic fabric varies, there is no one size fits all solution, and in many cases the options to improve the energy efficiency are subject to planning consent.
The Howard de Walden Estate in London’s Marylebone encompasses more than 200 listed buildings within conversation areas. Not surprisingly, the enhancement of the sustainability credentials of period property is a major focus for us. As the long-term steward of this unique part of London, we are responsible for retaining the beauty and heritage of period buildings, while repurposing and reinventing them for the 21st century. This includes decarbonisation and enabling our customers to live and work in increasingly energy efficient, comfortable buildings.
Seize the moment
When you put this triad of planning, technical and conservation challenges together, you’d be forgiven for thinking improving the energy efficiency of period buildings is an impossible task: it is not. It just takes an opportunistic approach. This means maximizing interventions and weaving them into maintenance and refurbishment plans, and where possible carrying out improvements at the same time to limit costs and disruption.
There are many triggers for upgrading energy efficiency. For us, achieving this type of retrofit depends on seizing the moment when we periodically get an entire building back pending reletting. Our current renovation of a Grade II listed, Queen Anne-style residential building is a case in point: after being let to the same customer for over a decade, it recently came back to us and was in need of rejuvenation.
As well preserving the heritage value of a building, the project sought to reduce carbon emissions by introducing a single air source heat pump. We added thermal insulation, along with LED lighting, low energy appliances and smart meters.
The project wasn’t without its challenges. When we considered the installation of solar panels, it became apparent it wouldn’t be viable due to the size of the roof and overshadowing from surrounding buildings. Instead, and to reduce the risk of the property overheating in summer, we will install a green roof to increase insulation and also encourage wildlife. Sometimes there have to be aesthetic compromises, too. We had no option but to lower some ceilings to accommodate the equipment and servicing needed. We hope to reduce emissions by over 70% when compared to the existing building and services.
Broader change
It’s clear that landlords can achieve a great deal with period buildings in terms of the drive to net zero, but hitting higher and higher energy ratings will be difficult without the further support of regulators and local authorities.
Evolving EPC ratings to acknowledge what is and isn’t achievable, and clarity on what lean, clean and green measures are generally acceptable in heritage assets would be a positive first step. Given that period buildings have a head start over ‘knock down and start again’ projects, they have an important role to play in reducing emissions and mitigating the effect of climate change.
As developers race to meet rigorous targets on new build, the reductions in emissions that can be achieved through sensitively refurbishing older buildings shouldn’t be overlooked. After all, historic buildings are inherently sustainable and have survived because they are not only robust, durable and adaptable, but have proven fit for the future time and time again.
